The active ingredient in DuPont Krenite Brush Control Agent is ammonium ethyl carbamoylphosphonate (fosamine ammonium salt, formerly known as DPX-1108). When carbonyl-labeled [14C]fosamine ammonium was administered as a single oral dose to preconditioned rats by intragastric intubation, the radioactivity was rapidly eliminated in the feces (87%) and urine (13%). Trace amounts of radioactivity were found in the gastrointestinal tract, hide, and exhaled air (0.1-0.2%). Less than 0.05% radioactivity was found in the body tissues after 72 h. Total recovery of applied radioactivity was nearly 100%. The eliminated carbon-14 in both urine and feces was 87% intact fosamine and about 13% carbamoylphosphonic acid. The synthesis of these compounds is described. © 1979, American Chemical Society. All rights reserved.
